Re: [PATCH v3 3/9] ACPI/IORT: Check ATS capability in root complex nodes

Lorenzo Pieralisi
2019-04-18T11:20:29Z

On Wed, Apr 17, 2019 at 07:24:42PM +0100, Jean-Philippe Brucker wrote:
> Root complex node in IORT has a bit telling whether it supports ATS or
> not. Store this bit in the IOMMU fwspec when setting up a device, so it
> can be accessed later by an IOMMU driver. In the future we'll probably
> want to store this bit at the host bridge or SMMU rather than in each
> endpoint.
>
> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
> ---
> drivers/acpi/arm64/iort.c | 11 +++++++++++
> include/linux/iommu.h | 4 ++++
> 2 files changed, 15 insertions(+)

For the IORT portion:

Acked-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>

> diff --git a/drivers/acpi/arm64/iort.c b/drivers/acpi/arm64/iort.c
> index e48894e002ba..4000902e57f0 100644
> --- a/drivers/acpi/arm64/iort.c
> +++ b/drivers/acpi/arm64/iort.c
> @@ -1028,6 +1028,14 @@ void iort_dma_setup(struct device *dev, u64 *dma_addr, u64 *dma_size)
> dev_dbg(dev, "dma_pfn_offset(%#08llx)\n", offset);
> }
>
> +static bool iort_pci_rc_supports_ats(struct acpi_iort_node *node)
> +{
> + struct acpi_iort_root_complex *pci_rc;
> +
> + pci_rc = (struct acpi_iort_root_complex *)node->node_data;
> + return pci_rc->ats_attribute & ACPI_IORT_ATS_SUPPORTED;
> +}
> +
> /**
> * iort_iommu_configure - Set-up IOMMU configuration for a device.
> *
> @@ -1063,6 +1071,9 @@ const struct iommu_ops *iort_iommu_configure(struct device *dev)
> info.node = node;
> err = pci_for_each_dma_alias(to_pci_dev(dev),
> iort_pci_iommu_init, &info);
> +
> + if (!err && iort_pci_rc_supports_ats(node))
> + dev->iommu_fwspec->flags |= IOMMU_FWSPEC_PCI_RC_ATS;
> } else {
> int i = 0;
>
> diff --git a/include/linux/iommu.h b/include/linux/iommu.h
> index 480921dfbadf..51ab006d348e 100644
> --- a/include/linux/iommu.h
> +++ b/include/linux/iommu.h
> @@ -446,6 +446,7 @@ struct iommu_fwspec {
> const struct iommu_ops *ops;
> struct fwnode_handle *iommu_fwnode;
> void *iommu_priv;
> + u32 flags;
> unsigned int num_ids;
> u32 ids[1];
> };
> @@ -458,6 +459,9 @@ struct iommu_sva {
> const struct iommu_sva_ops *ops;
> };
>
> +/* ATS is supported */
> +#define IOMMU_FWSPEC_PCI_RC_ATS (1 << 0)
> +
> int iommu_fwspec_init(struct device *dev, struct fwnode_handle *iommu_fwnode,
> const struct iommu_ops *ops);
> void iommu_fwspec_free(struct device *dev);
> --
> 2.21.0
>